Well of course. I was actually working in a hospital at the time. I had just completed my degree as a registered dietitian, and I was working with patients and counseling them on low fat diets. Here I was experiencing a dramatic, positive response in my own body to a very low carbohydrate diet. I always knew I wanted to go back to grad school and study nutrition and exercise. Shortly after working in hospital for a year I actually did that. I became obsessed with learning more about low carbohydrate diets.

Was it because you were surprised by your own body’s reaction. Or were you surprised that something that worked well for you was so widely condemned.

JEFF VOLEK

I think both. I certainly wasn’t learning about low carbohydrate diets in the classes I was taking. It wasn’t taught, and so I was doing this on my own in the library late at night, day after day, spending hours just trying to find as much research as I possibly could. And everything I was learning and reading about was supportive of low carbohydrate diets, and this was the early 90s, so this was before the resurgence in research of low carbohydrate diets. But there was actually quite a bit of work done back in the 60s and 70s. And of course Steve Phinney had published work in the 80s, and it all was very favorable, and it was shocking to me that this work was not followed up on and that we were promoting, carte blanche, low-fat diets with no caveats or recommendations for alternative approaches. So this became an obsession that really has continued on to this day to learn more about these diets, and I was fortunate in my graduate work to have the opportunity to study this. It was actually my dissertation to examine low carb diets. So for the last 12 years I’ve actively been pursuing research trying to answer the basic questions related to how humans and how people adapt to low carbohydrate diets.

Has it become your religion to study this?

JEFF VOLEK

Well I think as a scientist it would be reckless to say I view this as a religion but the analogy is not a bad in that people do view nutrition with sort of a religious vigor. The data should rule the day, and yet, in my experience talking about nutrition with my many colleagues and other researchers, they don’t like to deal with this data. I think a lot of scientists, when they deal with data that is in conflict with what they have been promoting for years, they deal with that in a way I would describe as cognitive dissonance. They don’t really criticize the data. At the same time they don’t embrace it. They ignore it, they reject my grants or reject my papers. And at the same time when you deal with these people face to face, and try to debate them, they often back down

When you say they back down, is it because they’re tired of hearing from yet another low carb advocate, or do you mean that when they actually listen, they start to agree

JEFF VOLEK

It”s quite common that they ignore us, and it’s probably fair to say that they do get tired of hearing this message, but it’s data. It’s hard science data, and it’s difficult for them to deal with. It’s an uncomfortable truth. I think many of them are coming to realize they built their careers on saying something different and so, I do in some way understand their reluctance to embrace this because their careers, and to some extent the livelihood of their labs, may be dependent on promoting an alternative message. And the message is, based on the science, we need to recognize that people vary widely in their ability to metabolize carbohydrate. So we have a carbohydrate tolerances.

A lot of people say that there is one best diet. The USDA certainly seems to say that. School lunch program certainly seem to say that. Is it your impression that people differ in what kinds of foods they do best with.

JEFF VOLEK

Absolutely. We have essentially a one-size-fits-all dietary recommendation and the fundamental problem with that is that we have a heterogeneic population that doesn’t respond uniformly to that diet. And this is not trivial because the number of people who really respond well to a low-fat diet is probably the minority of people. Most people have some degree of carbohydrate intolerance and so would actually benefit from restricting carbohydrate not fat. But that does vary from person to person, and so we should be seeking ways to find the right diet for the right person, and that probably starts with finding the right level of carbohydrate Some people may need to restrict carbohydrates to less than 40 g a day. Others may be able to tolerate 100 g per day. So it depends on the person. Most dietitians agree we need to embrace personalized nutrition. But that viewpoint is oddly juxtaposed with this sentiment that we all need to follow the dietary guidelines

When it comes to kids we have children that we know need glasses. We have children where we know that they need to sit at the front of a room otherwise they lose their attention. We have a lot of variation that we know in how children learn and how people learn and we acknowledge and we support. The one variation I can think of in children and the kinds of food they get, if they have a serious allergy to peanuts, we’ll watch out for that. Or if a child is overweight then we’re likely to tell the child to count calories more.

JEFF VOLEK

Focusing on counting calories is not the best approach. But coming back to your analogy of food intolerances, we’re very sensitive to people with lactose intolerance or gluten intolerance, and this is why introduced the term, carbohydrate intolerance. People have varying degrees of carbohydrate intolerance, and there’s a very strong physiologic basis for identifying that as a concept and if you view it in that perspective it’s a intuitive what you would do to a person with a carbohydrate intolerance – you would restrict carbohydrates, and that, in fact is what we have studied, and when people with carbohydrate intolerance restrict their carbohydrates below a level at which they metabolize it appropriately, all their clinical markers get better.

Now, we have a very low carbohydrate, very high fat, ketogenic diet for epilepsy – meaning a diet with such low carbs that the body is constantly in fat-burning mode and making a special, easy to use fat called a ketone. If a child has epilepsy a lot, one way to break the cycle, in many cases, is to restrict carbohydrates almost to nothing and feed a whole bunch of fat. In many cases after two years of that very extreme diet, a child can have pizza party, and in many cases, that child is now well enough to eat pizza without any more epileptic seizures. Could carbohydrate intolerance be the same? Could it be a diet that you don’t have to do it your whole life? Could it be like having a broken ankle, where if you rest the carbohydrate handling in the body, it gets well enough to handle carbs again? Is carbohydrate restriction just something you need for a little while?

JEFF VOLEK

Great question and we don’t have a lot of solid research studies, but observationally and my clinical experience, some people, when they restrict carbohydrates and lose significant amounts of weight, do improve their carbohydrate intolerance, such that they can, in a maintenance phase, reintroduce some level or carbs. However that’s not universally true. There are other people who will remain insulin resistant if they eat carbs, and even after they have lost significant amounts of weight. In order for them to maintain their weight loss and maintain their metabolic health, they need to continue to restrict carbohydrates indefinitely. So it really comes down to the person, and in many ways their underlying level of insulin resistance and whether or not that improves with weight loss. And some people, they’re just genetically programmed to have a level of insulin resistance. And the only way they can manage that is to restrict carbohydrates. That’s why we advocate a sustainable, very low carbohydrate diet for people that are on the far end of the continuum of carbohydrate intolerance.. Many people will be able to reintroduce carbohydrates and still see improvements in insulin sensitivity. But that has to be monitored on an individual basis and that’s where the tailored approach comes in, and each person has to chart their own path on this journey.

Charting your own path can involve measuring your hip to waist ratio and looking at how much you weigh, but it would be pretty neat to look in side our own blood and see if there is something there that is changing — one of those mysterious but important things we call blood markers. Are you seeing any blood markers you think would be good for people to monitor?

JEFF VOLEK

Objective markers certainly help people, in terms of having a having a number that they can use to help guide them down this path. You know at this point, a lot of it is subjective in that you look at the scale and look at how you feel and you look at if you have cravings for carbohydrates. These are all indicators that perhaps you are consuming too many carbohydrates But we are looking at biomarkers that would provide an early sign that your body is mismanaging carbohydrates. That really means that when you’re ingesting carbohydrate, a lot of it is being converted to fat in the body. And you don’t necessarily feel that And it does not show up right away in standard clinical markers But we are looking at some some biomarkers that would provide an early indication in converting dietary carbohydrate into fat, and this is causing a lot of collateral damage and sabotaging your weight loss efforts. So this might, down the road . . . we’re still validating this and hopefully it will be available sometime in the future.

In your book, the Art and Science of Low Carbohydrate Living, you mention this marker is called of a POA . What does that stand for

JEFF VOLEK

POA stand for palmitoleic acid. It’s a particular fatty acid that we have measured in blood that responds very sensitively to carbohydrate intake.

In some of your research that you’ve published, you’ve found s that sometimes people who do well on low carbohydrate diet and also do great on a high carbohydrate diet, either one – their POA levels stay low no matter what you’re feeding them. But other people if their POA level is low on a low carbohydrate diet, it will be climbing very quickly as you add carbohydrate back in. That’s what we’re studying, and it varies from person to person. Can you describe the new study?

JEFF VOLEK

What we’re doing now is are studying people who are essentially going through a dose response test of different levels of carbohydrates and we start them out at a very low level of carbs so that they’ll be adapted to fat-burning – that is, their body is producing ketones. They’re consuming about 35 g of carbohydrate per day. This is a heroic effort on the part of my dietetic students – we’re preparing all the food over a five and a half month period.

You know, 35 g of carbohydrate is not very much carb. It’s maybe two salads, and two bowls of leafy kale and half a cup of sliced onions and a half a cup of broccoli. That’s about it.

JEFF VOLEK

Actually, you’d be be surprised at the variety of foods you can incorporate into a 35-grams a day diet. In fact, our subjects have expressed great satisfaction with this diet. In fact, after they’ve through all the diets, they come back to wanting to go on the low carbohydrate diet.

What’s a typical lunch for 35 grams of fat?

JEFF VOLEK

They may have a salad with chicken on it and a high fat dressing, olives as garnishes. It’s rich, particularly in fat. It is not overly high in protein, which is a common misconception about low carbohydrate diets. It has non-starchy vegetables such as lettuce, cucumbers, radishes, broccoli, asparagus, cauliflower, etc. We’re taking these people through increasing levels of carbohydrate gradually, introducing carbs over time to identify a breakpoint, if you will. We want to know at what point do they start to divert the incoming dietary carbohydrate into fat, and our hypothesis is it will vary from person to person. Some people may be able to tolerate higher levels of carbohydrate; others may have a low tolerance. We’re also measuring POA, palmitoleic acid, in the blood as well as saturated fat in the blood and other standard clinical markers. We’re also trying to understand what is the best tissue to measure this particular fatty acid in. It has different concentrations in different cells and different lipid fractions in the blood so we want to understand the place to measure this in for people. So, we’re hopeful that, when this study is completed, we will have enough evidence and validation to launch this commercially, and it soon will be available for people to test and guide them to their own personal level of carbohydrate intolerance.

So you have the idea of using the POA, this marker to indicate at what level of carbs the carbs start to turn more quickly into fat.

JEFF VOLEK

Exactly, and that’s the key. This marker increases quite rapidly when your body’s converting carbohydrate into fat, more so than any other market we are familiar with it and more so than any other fatty acid. So it provides an early sign before you’ve started to gain weight and before your other markers, your triglycerides, for example, are elevated. This will tend to show up quicker, so people can use this as a guide to say, y look I’m dangerous zone. I’m still consuming too many carbohydrates, and my body’s not processing them in a healthy way.

What about all those people who have already gained weight? If they want to lose weight, could this marker also be good for them?

JEFF VOLEK

They still need to decide what level of carbohydrate they’re going to consume to lose the weight, and if their body is converting, even when they’re losing weight, still converting carbohydrates into fat, that’s not likely to result in a lot metabolic health, and it’s not likely to be sustainable. So I think it can be used initially to see where you’re at. Some people may not need to restrict, carbohydrates to 35 grams, if the POA level is still at an appropriate range, so it would help it would help to guide them to the appropriate level of carbohydrates to lose weight. But we think it’s in particular valuable as you enter into weight maintenance, because that’s where a lot of people get tripped up on low carbohydrate diets. They do quite well initially but then they reintroduce carbs into their diets for weight maintenance, and they exceed their carbohydrate tolerance, and that’s when they gain weight back. And that’s where you see a lot of recidivism in terms of weight gain and people enter into this yo-yo of cyclic rate loss then weight gain.

I wonder whether this approach might help no matter what diet someone choose. For instance, if somebody chooses a Joel Furhman, higher carbohydrate mostly vegan diet, and they restrict their calories for weight loss. Dean Ornish, Weight Watchers, any diet where you’re restricting calories, the challenge is always in the weight maintenance phase, to NOT gain the weight back. So this could be a clue for any of these diets about whether carbs are being converted quickly into fat.

JEFF VOLEK

Exactly and this test could be used really with any diet, but our assumption is that if you’re eating a low-fat diet is high in carbohydrates unless you’re very lucky and fortunate in terms of your metabolism to be able to process those carbohydrates then your POA level might be in that danger zone.

Now Jeff, how about someone who eats a lot of fat and very low carb. You can eat too much fat, can’t you?

JEFF VOLEK

You can. Certainly, calories matter, even on a low carbohydrate diet. But it’s my experience is that it’s very rare for people to overeat fat when you’re consuming carbohydrates at a level below your POA tolerance, because you are primarily burning fat for fuel, and you have a better fuel flow to all the cells in your body, including your brain, and you just don’t have those cravings and you don’t have the hunger and appetite issues that you have when you’re over consuming carbohydrates.

So you still think that even on a high fat diet, the good carbs could be the kindle that gets appetite started again, and this POA marker might be a way to figure that out.

JEFF VOLEK

I think so because when you’re keto-adapted, you at this remarkable ability to skip meals and not feel hungry, because your body’s relying on fat for fuel. Most people — even people who are very lean — have 40,000 kcal worth of energy in their fat stores. That can last them for several days, even if you exercise. So you can skip a meal, and you don’t have this fuel crisis for your brain because it can burn ketones or for your muscle cells because there’s plenty of fuel around. However if you’re depending on carbohydrates for fuel, and you miss a meal, that can turn into a crisis and that can trigger appetite of hormones and so forth which can lead to excessive consumption of calories.

Now you’re a weightlifter, and you could say what matters the most is burning excess calories through exercise. But you haven’t been talking that way. You’ve been focussing on food.

JEFF VOLEK

I’m a huge advocate for exercise. But the whole field of exercise science is much more complex than we make it out to be. If you’re using exercise as a weight-loss tool, that’s different than using exercise to excel at sports. So we have to be careful in how we prescribe exercise for people. It’s very contextual. For example, in many people exercise is a very poor weight loss tool.

They just get hungrier.

JEFF VOLEK

They get hungrier, and their metabolic rate goes down. So simply telling people to exercise more to lose weight doesn’t work very well. That’s been born out in many studies now. But if you’re an athlete and you want to improve your performance, obviously training the right way, which is a whole other issue, is important. I’ve always been a huge supporter of nutrition being critical to experience the optimal benefits in a training program. So you may have the best training program in the world, but if you don’t eat the right fuel to perform the exercise and to recover from exercise – there is a whole new area of recovery nutrition now, But if you don’t have the right nutrition, you won’t experience the benefits of the training programs. So that’s why it’s so important to be integrating the fields of nutrition and exercise to optimally affect performance and health. And there are so many misconceptions and mythologies about nutrition and exercise that it can be a minefield to navigate through.

Is that why you’re written this new book on the Art and Science of . . . .

JEFF VOLEK

The Art and Science of Low Carbohydrate Performance, which is more or less an addendum to our previous book I wrote with Dr. Steve Phinney – The Art and Science of Low Carbohydrate Living. Really the first book was geared more toward healthcare professionals, and trying to empower them with the knowledge to teach low carbohydrate diets and their clinical application. But Steve and I are both athletes and have actually studied low carbohydrate diets in the context of endurance and strength performance, and we have a lot of athlete friends who said, hey what about us? Can we benefit from a low carbohydrate diet? So we wrote this book down to specifically address the low carbohydrate athlete who wants to go against the grain, so to speak, and is not interested in carbohydrate loading and all the sugary carbohydrate drinks and can they actually perform exercise with very little carbohydrate. The answer is with a couple of weeks of adaptation to a low carbohydrate diet, yes, they can perform this way, and sometimes even better.

Does this low carb diet for athletes work best for athletes in endurance sports and should sprinters stay away from it?

JEFF VOLEK

That’s a great question. Clearly from a metabolic standpoint, being able to burn fat more efficiently is incredibly valuable to an endurance athlete. Especially the ultra endurance athletes who are exercising for two hours or longer. You’re going to run out of carbohydrate and glycogen in your body. You’re going to run out of fuel very quickly. So being able to utilize fat efficiently is incredibly valuable. So strength athletes and high-intensity athletes they are performing at an exercise intensity that may rely on glycogen, so it’s not as clear cut how they would benefit. But many of these athletes, on a low-carb diet, lose body fat. They maintain their muscle mass while losing body fat, so this improves their power to mass ratio. So they’re more powerful and they have more energy to do their training but they don’t lose their muscle endurance and their strength, so this is a valuable adaptation for even strength athletes.

So would you suggest to a sprinter, perhaps, train on a low carbohydrate diet, and then on race day or two days before, go ahead an eat that big plate of pasta?

JEFF VOLEK

It’s possible and this is one approach. We haven’t formally studied this idea of reintroducing carbs strategically, or around workouts or before a race, But anecdotally, I know athletes in Europe who follow this concept of, train on a low carbohydrate diet to induce a lot of the positive metabolic adaptations, and then, before an event, carb load. I think it does make some sense, but this hasn’t been really studied intensely and it would be a little concerned about that approach if people were just exercising for metabolic health, and they had carbohydrate intolerance, because that might set them up to potentially exacerbate some of their metabolic problems by reintroducing carbs — even a single carbohydrate meal can allow them to lose some of their metabolic adaptations that they have achieved with a low carbohydrate diet. So switching back and forth is not something they can do efficiently, compared to an athlete who is insulin sensitive. So there are some caveats with that approach. But for myself, I was a a power lifter, and I was using low-carb diets to help maintain my body weight. I was competing in a weight class where I tried to be as lean as I could without exceeding a specific weight, and I found it was very effective to maintain my weight near my competition weight, whereas my colleagues would try to lose 20 to 40 pounds before a meet and sometimes lost a lot of strength too. So it does have implications for power lifting.

How much do you weigh and how much weight did you used to lift?

JEFF VOLEK

When I was competing, I was a little heavier than I am now. I was competing in the 181 pound weight class.

And how tall are you?

JEFF VOLEK

I’m 5′ 10″, and my best squat at that weight was 600 pounds at that weight. And I also dead-lifted 600 pounds. My bench press was not as good. It was 330 pounds. Those were respectable but not good enough to compete in national or international competitions, but it allowed me to have fun, and I enjoyed it.